The video below is from the Smithsonian and provides some tips for safe removal.

After seeing some examples of photo album horror stories online, I feel pretty fortunate that my photos came out the albums as easily as they did. However, the glue from the magnetic pages is stuck on the backs of some of the photographs. I'm guessing that this could present some problems if the photos will be stacked together for long term storage. Before these photos are filed away, I'm going to make sure that I scan the "keepers" so that further damage can be prevented. I suppose that going back to my original negatives might also be an option. But that is probably going to be like looking for a needle in a haystack. I wonder if I still have a light box around here somewhere . . .

I've recently started trying to go through our old family magnetic albums - so much work! Ugh. I've had to go back to the negatives several times and I'm so glad that I did because I was amazed how much better the image from the negative was than the photo in the album. The images really faded and yellow in the album and after scanning the negative I was able to have great colored and crisp images.